Published 5:30 am, Thursday, October 26, 2006

The third insect to have its DNA sequenced — following the fruit fly and the mosquito — the honeybee is the most genetically similar to humans:

The third insect to have its DNA sequenced — following the fruit fly and the mosquito — the honeybee is the most genetically similar to humans:

Photo: KAIA LARSEN, AP

Houston scientists sequence honeybee DNA

1 / 1

Back to Gallery

A team led by Houston scientists has sequenced the genome of the humble honeybee, a move researchers hope will bring them a small step closer to understanding the genetic causes of human disease.

By going beyond a traditional team of geneticists and including honeybee specialists from 16 nations, the project has created considerable scientific buzz and resulted in the release Wednesday of more than four dozen research papers.

Some of the immediate results include an understanding of the shocking rate at which the genes of Africanized bees, breeding with European bees in southern Texas, have dominated their more docile cousins.

"Enablement is the main goal of a genome project, to get a genome sequence, analyze it for the gene list and engage with the community who will use it in research," said George Weinstock, a genetics professor at Baylor College of Medicine and director of the honeybee sequencing effort.

The honeybee genome will be published in today's issue of the journal Nature.

Latest News Video

Honeybee social behavior in hives, with a caste system of queens, workers and drones, will help scientists understand how genes regulate human social behavior by comparing the two sequences. This could lead to insights about diseases such as schizophrenia or Alzheimer's.

"This DNA sequence is a major step towards answering a basic question of social evolution: At the genomic level, what does it take to engineer an advanced colonial insect?" wrote Harvard University biologist E.O. Wilson in a Nature commentary assessing the new genome's impact.

Researchers who have studied the honeybee genome also are intrigued by the potential for studying immunity. Honeybees live in crowded, warm hives, where diseases should be easily transmitted. Yet the honeybee genome has comparatively fewer "immunity" genes than other insects, suggesting they may possess novel means of protecting themselves from illnesses.

Function of genes

Scientists have at least draft genome sequences of more than three dozen animals, including humans, cats, dogs and cows, all coming since February 2001, when a draft of the human genome was completed. Baylor has been involved in sequencing more than 30 genomes, from humans to bacteria.

Why sequence all these genomes, and the hundreds more of animals, plants and bacteria that are on the way?

Richard Gibbs, director of Baylor's Human Genome Sequencing Center, said the goal remains understanding the genetic causes of human disease. Doing that requires understanding the function of individual human genes, which can be accomplished by determining which genes humans share with other species.

'A complete lineage'

Because of vast computing power increases and technical advancements, Gibbs said that within five years genetic researchers should be able to pinpoint in which ancestors, and at what time, every single human gene came into existence.

"We will soon have a complete lineage of all human genes," he said.

The bee genome could have a more immediate impact on the $15 billion pollination industry, in which researchers are becoming concerned about declining populations of honeybees. Some 90 commercially grown crops are pollinated by honeybees. A National Academies report released last month called for increased monitoring of honeybee populations, and, potentially, conservation actions.

New subspecies of bees

Among those could be developing hardier bees, such as the infamous African "killer bee," which reached the Western Hemisphere 50 years ago, and spread into South Texas in 1990. Since then, scientists report after studying bee populations in South Texas, the Africanized bees have mated with two European types previously introduced to the United States.

The natural breeding has created a new subspecies of bees, said J. Spencer Johnston, a professor of genetics at Texas A&M University. About two-thirds of the genes in the new sub-species belong to the Africanized bee, suggesting a stunning "biological invasion."

Johnston said the genome data could help scientists determine whether the genes of Africanized bees have been transferred to the new species or explain why Africanized bees have been less lethal than predicted.

Beekeepers may derive considerable benefit, he said. Africanized bees have some resistance to Varroa mites, which have devastated some honeybee colonies. The goal, then, is developing a bee with the desirable traits of Africanized bees and their more docile European counterparts to create a healty, pollinating, honey-making bee.